Intrlock



May 20, 1941. w. F.' REGENHARDT INTERLOGK Filed Nov'. '12, 1938 j n'lm E INVENTOR lfcgcn fim'd'l' BY mam/:1

I W ATTORNEY Patented May 20, I941 UNi'l'EB STATES PATENT OFFICE INTERIDCK Walter F. Begenhardt. Cleveland, Ohio Application November 12, 1938, Serial No. 240,178

The present invention relates to mechanical interlocks which can be readily applied to or removed from the elements to be attached.

One of the objects of the present invention is to provide for interlocking two elements, for example, relatively rigid sheet material such as sheet metal, molded sheet material, fiber board, in which a locking member, formed on one of the elements, projects through an opening in the other element and the projecting part is provided with a key receiving opening and a shoulder, a key being provided having a leg adapted to, extend into the opening in the projecting part and having a section which is adapted to extend alongside the projecting part and which includes a shoulder which is arranged to abut the shoulder on the projecting part to prevent accidental removal of the key.

Another object is to form the key of flexible and resilient material so that the leg and section can be flexed, relative to one another, when the key is being attached or being removed.

Another object is to utilize the key as a camming device for the purpose of forcing the elements which are to be interlocked, toward one another.

Other and further objects and advantages will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred form of embodiment of the present invention is clearly shown.

In th drawing:

Fig. 1 is a plan view of one of the elements to be interlocked;

Fig. 2 is a plan view of the other element;

Fig. 3 is a plan view'of the key for interlocking the elements shown in Figs. 1 and 2;

Fig. 4 is a plan view of the elements shown in Figs. 1 and 2, the element shown in Fig. l resting on the element shown in Fig. 2, and, showing the key about to be applied to interlock the elements;

Fig. 5 is a sectional view taken on line 5-5 of Fig. 6; and

Fig. 6 is a plan view on a smaller scale showing the key and elements in interlocked position.

Referring to the drawing, for the purpose of illustrating one embodiment of my invention I have selected two sheets of material which are to be interlocked. These sheets may be of any shape or configuration, for example, the confronting faces thereof may be arcuate and if so, the interlocking key may be shaped to conform to the shape of the confronting faces. However, to simplify the illustration, I have selected two flat sheets. These sheets are more or less rigid and may be sheet metal, molded material, such as Bakelite, molded fiber board, etc. One of these sheets is shown as 21 and the other at 28. Sheet 21 is provided with an opening 58 which is arranged to receive a bulged portion or locking member 42 on sheet 28. The opening 4| conforms substantially in width and length with that of bulged portion 42. If sheet 28 is metal, the bulged portion would be formed by a drawing operation to form arecess 43 on the underside thereof. Also the sheet would be pierced or in any way suitably cut to provide an opening 65 forming the mouth to the recess 43. The side of the portion, opposite the opening 44, provides a shoulder 45 and the underside provides an abutment #36.

when the sheets 2? and 28 are superimposed, the top part of portion 62 projects through the opening 45 in sheet 2? so that part of th mouth 44 is above the top of sheet 2?.

The sheets Zl and 28 are interlocked by a key t'l." This key is formed of flexible resilient material, for example, it may be a stamping of sheet metaL- Key it includes a leg 48 which merges into a yoke section 49. A leg section is formed integrally with yoke section 49 and includes preferably two legs 50 disposed on opposite sides of leg 48. This leg section includes a portion 52 forminga shoulder facing the free end of leg it. When two legs 50 are employed,

portion-52 is'in the form of a connecting yoke. Consequently the edge of the yoke forms a shoulder 53 facing toward the free end of leg 48. The leg it is provided with a ridge 5| which starts 'rearwardly of the free end of the leg.

In the attached position, leg 48 projects through opening 44 in locking member-42 and 'legs 50, yoke 52 and yoke section 49 surround the projecting part of member 42. The shoulder 53 on yoke 52 is arranged to engage shoulder (it or member 52 to prevent the accidental removal of the key from its locking position. Preferably the ridge 5i frictlonally engages the abutment it and sections 50 and 52 frictionally engage the top surface of sheet 21 when in position.

In attaching the key 81, it is first placed in the position shown in Fig. 4 in which the yoke 52 overlaps the rear end of member 42. Then leg 48 is depressed to align the same with the opening 44 in member 42. Simultaneously, it is pulled forwardly so that the fore part thereof will enter the opening 44. Finally it is forced into the position shown in Fig. 6. Obviously section 50 must be flexed relative to leg 48 when the key is being attached because the over the top of. member I! while the leg passes underneath the top of member 42, however, the material of the key is resilient and after yoke 52 is pulled beyond the shoulder ll, it will be flat upon the sheet 21 with its shoulder 53 in abutting relation with shoulder 45. likewise legs 50 will lie fiat upon sheet 21.

The fiat fore part of leg I can be readily inserted into the mouth 44 of member 42 although the mouth extends only a short distance above sheet 21. The fore part of ridge ii slopes upwardly gradually and therefore functions as a cam'and when the key 41 is pulled into position, it bears on the abutment u of member 42 and since the sections 4! and II bear upon the other sheet. the sheets are forced into binding relation with one another. Thus it is apparent that the key 41 can be readily attached although the confronting surfaces of the sheets are warped orbent, for example, the material of sheet 28 may be bulged downwardly about the locking member 42 or the material of sheet I! may be bulged upwardly about the opening 41 and, in either event, the fore part of leg 4| can be readily inserted into the mouth 44 and the confronting walls will be cammed toward and into binding relation with one another by the ridge 5i when the key is pulled to locking position.

The material from which key 41 is formed is sumciently flexible so that the yoke 82 can be lifted either by ones finger or a small tool, and in order to unlock the sheets, it is necessary only to lift upwardly on the yoke 82 and push rearwardly on the key.

From the foregoing, it will be seen that I have provided an interlock which is inexpensive and simple to manufacture, which also functions to camv the elements, to be attached, toward one another and, constructed so that the locking key itself is latched in position when the key is in interlocking position.

While the form of embodiment of the present invention as herein disclosed constitutes a preyoke I: must pass ferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

Iclaim:

1. In combination, an element having an opening therethrough; a wall formed of sheet material and having a bulged portion, said portion extending through the opening and having an opening in one end thereof and a shoulder opposite the last mentioned opening; and a key for locking the bulged portion in the first mentioned opening, said key comprising a member formed of resilient sheet material and having a yoke, a leg extending from the yoke and in the second mentioned opening when the key is in locking position, and a section extending directly from the same side of the yoke and alongside the leg,

said section having a shoulder for abutting the first mentioned shoulder when the key is in looking position, said yoke, leg and said section being flexible with respect to the leg so that the portion of the section including the second mentioned shoulder can be raised over the bulged portion when the leg is inserted or removed from the second'mentioned opening.

2. In combination, an element having an opening therethrough; a wall formed of sheet material and having a bulged portion, said portion section being disposed substantially in the same plane,

section having a shoulder posite the last mentioned *and alongside the leg.

, extending through the opening and having an opening in one end thereof. and a shoulder opopening, said bulscd portion including a wall forming an abutment facing the element; and a key for locking the bulged portion in the first mentioned opening, said key comprising a member formed of resilient sheet material and having a yoke, a leg extending from the yoke and in the second mentioned opening when the key is in locking position, and a section extending directly from the same side of the yoke and alongside the leg, said for abutting the first mentioned shoulder when the key is in locking position, said yoke, leg and section being disposed substantially in the same plane, said section being flexible with respect to the leg so that the portion of the section including the second mentioned shoulder can be raised over the bulged portion when the leg is inserted or removed from the second mentioned opening, and a ridge formed on said leg, said ridge extending from the yoke and terminating short of the free end of the leg, said ridge engaging the abutment when the key is inserted in looking position.

3. In combination, an element having an opening therethrough; a wall formed of sheet material and having a bulged portion extending through the opening, said bulged portion having an opening in one end thereof and a shoulder opposite the opening therein; and a key for locking the bulged portion in the first mentioned opening, said key comprising a member formed of resilient sheet material and having a yoke, a leg extending from the yoke and into the second mentioned opening when the key is in locking and a section extending directly from the same side of the yoke and spaced from the leg, said section extending around the end of the leg, the edge of said section adjacent'the end of the leg abutting the shoulder when the key is in the locking position, said section being flexible that the free end of the section can be raised over the bulged portion or removed fromlockleg and section being the same plane.

ing position, said yoke, disposed in substantially 4. In combination, two to side relation, one of said walls having an opening therethrough; means forming a shoulder adjacent the opening, said shoulder extending outwardly with respect to said one wall, and a bulged portion extending through said opening and outwardly with respect to said .one wall, said bulged portion being connected with the cooperating with an edge the same side of the yoke said section having a shoulder for abutting the first mentioned shoulder when the key is in looking position, said yoke, disposed substantially in 

